Cell Cycle and Cell Structure
2006-11-01 23:16:23 · 6 answers · asked by Gursharan 1 in Science & Mathematics ➔ Biology
Cell division is a means of replacing worn out or dead cells.
If you're asking ;Why do cells divide?
Couple of theories:
1. Ratio of the size of the nucleus to the volume of the cytoplasm:
The nucleus controls the cell. When the cytoplasm gets too big for nuclear control, the cell splits.
2. Ratio of the volume of the cytoplasm to the surface area of the cell membrane: Materials are transported into and out of the cell through the cell membrane. If the cytoplasm gets too big, the cell membrane cannot take in enough needed materials. The cell splits, thus creating more cell membrane surface area.
Mathematically: As the radius of a spherical cell increases from 1 to 2, the volume of the cell increases much more (I believe 8X more) than the surface.
Additional note: Cell division and growth are two different things.
When a cell divides, you just have two cells, 1/2 the size of the original. Growth follows!
2006-11-01 23:42:37 · answer #1 · answered by ursaitaliano70 7 · 0⤊ 0⤋
Cells divide either by mitosis or by meiosis.
Mitotic division usually takes plce to regenerate cells lost due to injuries, blood loss,etc. Mitosis is vital for growth; for repair and replacement of damaged or worn out cells; and for asexual reproduction, or reproduction without eggs and sperm.
Cells divide by meiosis ususally to perpetuate,i.e. to reproduce. Meiosis ensures that reproduction will produce a zygote that has received one set of chromosomes from the male parent and one set of chromosomes from the female parent to form a full set of chromosomes. The entire set of chromosomes in an organism is known as the diploid number. Once formed, the zygote continues to divide and grow through the process of mitosis.
2006-11-01 23:57:06 · answer #2 · answered by kalyan r 3 · 0⤊ 0⤋
Most life requires progeny to have its DNA persist. During mitotic cell division DNA is synthesized and the chromosomes are doubled. The cell during anaphase will pull the homogolous chromosomes apart and telophase the cell is cleaved in two. The nuclear envelope is reformed and you have two identical cells. Thus its DNA is still in existance.
2006-11-01 23:49:09 · answer #3 · answered by David K 2 · 0⤊ 0⤋
To continue to exist.
2016-11-12 00:23:53 · answer #4 · answered by Anonymous · 0⤊ 0⤋
To grow.
2006-11-01 23:23:17 · answer #5 · answered by rrrevils 6 · 0⤊ 0⤋
to grow
2006-11-01 23:23:31 · answer #6 · answered by frediks10 3 · 0⤊ 0⤋